The Native American House Alliance of Philadelphia holds an annual powow at Shackamaxon, "the place where Chiefs are made" -- also known as Penn Treaty Park -- to honor the Treaty of Friendship between the Lenape leader Tamanend and the Quaker leader William Penn, which Native Americans call the only treaty with the Europeans that has never been broken.  

"Everybody Dance!" was the call, and as this photo shows, a lot of us did.